Taiwanese patent no. 1321081 discloses a socket wrench 1, as shown in FIGS. 1 and 2. The socket wrench 1 includes a head 11, a tubular shaft 12, a handle 13, first and second biasing units 14, 16, and two C-shaped hoops 15. The head 11 includes two lugs 112 and a driving stud 111. A socket (not shown) may be coupled to the driving stud 111 for turning, for example, a nut. The tubular shaft 12 extends through slots of the lugs 112, and the handle 13 is inserted through a through bore 121 of the tubular shaft 12 so as to be movably retained in the tubular shaft 12. The two C-shaped hoops 15 respectively engage two opposite ends of the handle 13 so as to prevent undesired removal of the handle 13 from the tubular shaft 12 through the through bore 121. The first biasing unit 14 includes a spring 141 and a steel ball 142. The spring 141 is disposed in an outer surface of the tubular shaft 12, and biases the steel ball 142 to extend outwardly of the outer surface of the tubular shaft 12. When two opposite ends of the tubular shaft 12 are respectively journaled in the slots of the two lugs 112, the steel ball 142 is urged by the spring 141 to engage one of the lugs 112. The second biasing unit 16 includes a spring 161 and a steel ball 162. The spring 161 is disposed in an inner surface of the tubular shaft 12 which defines the through bore 121, and biases the steel ball 162 to extend into the through bore 121. When the handle 13 extends through the through bore 121, the steel ball 162 is urged by the spring 161 to engage the handle 13 so as to permit the handle 13 to be slidably engaged with the tubular shaft 12.
In the conventional socket wrench 1, although the handle 13 is linearly slidable to permit the socket wrench 1 to be used in a limited space, the handle 13 is also rotatable about its lengthwise axis. Thus, when the conventional socket wrench 1 is used to turn a nut (not shown), a force applied to the handle 13 might cause rotation of both the nut and the handle 13, hence requiring exertion of a greater force for tightening the nut.
In addition, as shown in FIG. 2, due to the provision of the C-shaped hoops 15, the handle 13 and each of the lugs 112 are spaced apart from each other by a gap (g). Because of the presence of the gap (g), a force exerted on the handle 13 to turn the handle 13 cannot be evenly distributed to the lugs 112 so that the handle 13 may crack due to stress concentration.